Switch and signal control system for railroads



2, 1942. c. L. sw AN'roN SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADSFiled ma 2, 1940 2 Sheets-Sheet 2 II I I I i I i I I I I l I L a8 4lllll Ir um zzm 3% =61 6v fin Q M 12 650 L 3.50 3935 8 A 35:8 2. w Q Tv. b

Patented June 2,1942 J SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADSCharles L, Swanton, North Chili, N. Y., assignor to General RailwaySignal Company, Rochester, N. Y.

Application May 2, 1940, Serial No. 332,971

This invention relates to switch and signal 1 11 Claims.

I control systems for railroads, and it more particularly pertains tothe power operation vof track,

switchesin a switch. and signal control system of the entranceexit type.

In an entrance-exit switch and signal control system, a control machineat a: tower or control ofiice is provided with a control panel uponwhich is a miniature track diagram corresponding to a track layout inthe field for which the system is provided. Disposed on such diagram atpoints representative of the signal locations are control buttons by theactuation of which an operator can designate the entrance and exit endsof each route he desires tobe set up. Responsive to such designation,a'route establishing means such; for example, as is disclosed in theprior application of A. Langdon, Ser. No. 119,641, filed January 8,1937, and in the patent to A. Langdon, Patent to the control wires ofsuch device."

More specifically, for example, the control circuits for operating thetrack switches to opposite positions from those positions such trackswitches have last assumed, are maintained closed and deenergized at alltimes except when such opposite positions of the track switches arecalled for, each of such circuits including a polar cross protectionrelay located at the control ofiice. Thus,

if a cross occurs between the normal or reverse control wires of twopower switches, the application of energy to either of such wirescausesthe operation of the cross protection relay for the track switch havingits control wire improperly V energized, if such energy is of the properpolarity to cause such track switch to be operated.

The detection of a, cross by a cross protection re-- lay under suchconditions trips a circuit breaker to immediately deenergize all of theswitch control circuits and thus remove energy from the circuitimproperly energized. After the cross has been removed, the crossprotection relay and theci'rcuit breaker are respectively manuallyrestored to their normal conditions.

Another object of the present invention is to open the switch controlcircuit last used for the operation of a track switch at the controloflice when that track switch has completed its operation, thusrendering the normal and reverse switch control wires both deenergizedexcept when r the track switch is out of correspondence with thelastposition called for. It is further provided when such circuits aredeenergized that the normal and reverse switch control wires are bothconnected through the winding of the cross protection relay for thattrack switch to a common switch control wire.

Another object of the present invention is to provide in anentrance-exit system dynamic braking for each of the switch machinemotors when that switch machine has completed its operation, suchdynamic braking being dependent upon the closed circuit principle asused in connecticn with the cross-protection means employed.

Another object of the present invention is to provide in anentrance-exit system an arrangetrol oliice for use in connection withthe crossprotection means.

Other objects, purposes and characteristic features of the presentinvention will be in part obvious from the accompanying drawings and inpart pointed out as the description of the invention progresses.

In describing the invention in detail reference will be made to theaccompanying drawings in which like reference characters designatecorresponding parts, in which parts having similar functions aredesignated by similar letter referi ence characters having distinctivepreceding numerals or preceding letter reference characters indicativeof the signal locations withwhich such parts are associated, and inwhich:

Figs; 1A and 113, when placed end-to-end, illustrate one embodiment ofthe present invention as applied to the power operation of the trackswitches of a simple track layout in accordance with the entrance-exitdesignation of each desired route to be established by the actuation ofrespective entrance and exit buttons by an operator at the controloffice.

The various parts and circuits constituting the embodiment of thepresent invention have been shown in a diagrammatic manner rather thanshowing the specific construction and arrangement of parts as providedin practice, for the purpose of facilitating the disclosure of thepresent invention as to the mode of operation and principles involved.Thus, the various relays and their contacts are illustrated in aconventional manner, and symbols are used to indicate the connections tothe terminals of batteries or other sources of electric current insteadof showing all of the wiring connections to those terminals.

The symbols and are employed to indicate the positive and negativeterminals respectively of suitable batteries or other sources of directcurrent, and the circuits with which those symbols are used always havecurrent flowing in the same direction. If alternating current is used,the symbols and are to be considered as relatively instantaneouspolarities.

For convenience in describing the present invention reference is madefrom time to time to parts of a general nature as characterized by theletter reference characters common to such parts. Such reference is tobe considered as applicable to any of the parts designated in thedrawings by similar letter reference characters having precedingnumerals or letters representative of the various signal locations.

Track Zay0ut.-Although the present invention is applicable for use withpractically any track layout encountered in practice, for the purpose ofsimplifying the disclosure of the present invention, the embodiment ofthe invention as illustrated in Figs. 1A and 1B is applied to thegoverning of train movements through the track layout illustrated inFig. 1B. It is to be understood that the system provided for the controlof each of the track switches in such track layout is typical of themeans by which the system is applied to the control of single trackswitches and crossovers of any particular complex track layoutencountered in practice. The track layout illustrated in Fig. 1B is atype which might be encountered in practice at either end of a stationplatform, there being a more direct through route, and two other tracksassumed to be coming from different platforms converging by respectivetrack switches into a single track extending away from the stationplatform.

Signals are provided for governing traffic through the track layout,signals A and B governing east bound traffic to the right through thetrack switch 2, and signals D and E governing east bound trafiic throughthe track switch 3. West bound traffic to the left through track layoutis governed by signal F through track switch} and by signal C throughtrack switch 2. For the purpose of simplicity, it is assumed that eachof the signals governing traffic through indications being distinctiveby the illumination of green lamps, for example, in accordance withautomatic control dependent upon the condition of occupancy of thetrackway in advance of such signals and dependent upon the indicationdisplayed by the next signal in advance. It is also to be understoodthat other types of signals such as semaphore and search light signalscan as well be used.

Each of the track switches 2 and 3 is power operated by a switch machineSM, the switch machine ZSM being provided for the positioning of trackswitch 2, and the switch machine 3SM being provided for the positioningof track switch 3. Each of the switch machines SM can be, for example,of the type disclosed in the patent to W. K. Howe, Patent No. 1,466,903,dated September 4, 1923, and in addition to the structure dis- L closedin that patent such switch machine can also contain a brake as disclosedin the patent to W. K. Howe, Patent No. 1,8525%, dated April 5, 1932,and associated with the switch machine a point detector contactmechanism can be provided as shown, for example, in the patent to C. S.Bushnell, Patent No. 1,517,236, dated November 25, 1924.

A polar neutral relay WP is provided for each of the track switches forrepeating its position in correspondence with the switch machine forthat track switch in a manner well known to those familiar with the art.Each of such WP relays is energized with one polarity when its trackswitch and switch machine are locked in a normal position and isenergized with the opposite polarity when the track switch and switchmachine are locked in a reverse position, such WP relay beingdeenergized except when either of those two conditions is fulfilled.

The track layout is divided into track sections in the usual manner,there being detector track section 2T for the track switch 2, and adetector track section 3T for the track switch 3. It is to be understoodthat the usual type of track circuits is provided for each of the tracksections for the energization of its respective track relay TR in amanner well known to those familiar with the art, and that the trackswitches are properly bonded to provide fouling protection.

System device.With reference 'to Fig. 1A, a portion of the miniaturetrack diagram of the control panel of the control machine for governingtrain movements through the track layout illustrated in Fig. 1B isshown, such portion being for trafiic through the portion of the tracklayout conveniently called an interlocked group bounded by signals A, B,and C. Inasmuch as such interlocked group corresponds in generalcharacter to the adjacent interlocked group bounded by signals D, E andF, for the purpose of simplicity, the portion of the control machinerelative to the control of such adjacent interlocked group has not beenshown, as it is believed to be readily apparent to those familiar withthe art that the means for governing traffic through such interlockedgroup is practically.

identical to that illustrated in detail and about to .be described forthe group bounded by signals A, B and C. Thus, with reference to Fig.1A, entrance buttons ANB, BNB and CNB are provided on the control panelat points in the miniature track diagram corresponding to the relativelocation of the signals A, B and C for designation of the entrancepoints for routes to be established governed by such respective signals.In a similar manner, the exit buttons AXB, BXB and CXB are provided fordesignation of the exit points for the respective signal locations A, Band C.

Each of the entrance buttons NB is of the self-restoring type, having acontact closed only when the button is depressed and *another contact.closed when such button isin either a normal or a depressed position,but opened if such button is pulled out from its normal position Each ofthe exit buttons XBis a the selfrestoring type having a contact closedonly when such button is depressed from its normal position Althoughseparate entrance exit buttons NE and KB are provided for thisembodiment of the 1 present invention, it is desired to be understoodthat a single button can aswell be provided for each of the signallocations for designation of both entrance and exit points at suchlocation,

there being circuit or structural Ineans'provided for differentiatingbetween the various entrance and exit operations in the designation ofthe various route ends.

Associated with the establishment of each-route through the track layoutresponsive to the dos-- ignation of its ends by the actuation of the emtrance and exit buttons are relays NR, XR, Y, N, R, WZ, L, LS, NCR, RCRand G which are provided in a manner and for purposes substantially asset forth for relays designated by similar letter reference charactersin thea'bove mentioned patent to A. Langdon, Patent No. 2,148,865, datedFebruary 28, 1939. Each of the relays NR is associated with a particularentrance point and is energized responsive to entrance designation, suchrelay being maintained energized, dependent for restoration upon passageof a train, or upon the pulling out of the entrance button NB for thatentrance point. Each of the exit relays XR is associated with aparticular exit point and is energized responsive to exit designationfor that point subsequent to the designation of an entrance point, suchexit relay being maintained energized, dependent for deenergization uponthe deenergization of the entrance relay NR for the opposite end of.that route. The relays N and R are provided for selecting the respectivenormal and reverse posi tions of the track switch with which they areassociated, and such relays are selectively enere gized in accordancewith the p-reselecting relay Y for that track switch, responsive to thepick-- ing up of the exit relay XR for the exit end of the route to beestablished.

The polar neutral switch control relay W2 is responsive to theenergization. of' an N or R switch control relay for that track switch,the function of such relay being primarily to provide distinctiveenergization of the relay W Z for that track switch, and such relays areprovided with heavy duty contacts for closing and opening the switchoperating circuits, having magnetic blow out means for extinguishing theare at such contacts. Such relays also provide circuit means forselectingthe switch control circuits in a manner to facilitate theprovision of features of the present invention relative tocross-protection, and the provision of dynamic breaking for the switchmachine motor with which such relays are as sociated.

A polar cross-protection relay P is provided for each of the trackswitches, only one of such relays 2P being illustrated in Fig. 13. Suchpolar relay can be constructed as shown, for example,

in the patent to W. S. Henry, Patent No.

1,030,811, dated June 25, 1912, there being a but- 1 ton providedthereon for the restoration of the armature of such relay. 7

Associated withthe means for cross-protection, is a circuit breakerC13,, which is tripped whenever any one of the cross-protectionrelays Pis operated by a cross occurring in the control circuitsof any one ofthe switch machines included in the track layout.

Having thus considered in a general manner the organization of theapparatus for this embodiment of the present invention, it is believedto be expedient to describe the mode of opera-' tion and the principlesinvolved with specific reference tofvarious operating conditions.

Operation ing this embodiment of the present invention,

su'fllcient description of the route establishing means will be includedto point out its mode of operation in a general manner, and referencewill be made to specific examples, showing how the system functions ingoverning the simple track layout used in connection with thisembodiment of the present invention.

Normal conditions-The conditions assumed to be normal are those existingwhen the track layout is unoccupied by trains, there are no routesestablished or partially established, and the signals are all at stop,An operator is aware of such normal conditions by the indicator lampsmal conditions, in the position last required for a route including suchtrack switch, and it has been assumed the last route established throughthe track layout to be a through route on the lower track requiringthe'track switches 2 and 3 to beoperated to their respective normalpositions. l

Under normal conditionsthe lock relay 21. is energized dependent uponthe route locking, detector locking, approach locking, or time lookingprovided in accordance with the require-- ments of practice in a mannerwell known to those familiar with the art, A lock stick relay 215 ismaintained energized uponnornial con}: ditions dependent upon the lockrelay 2L by a circuit closed from including front contact II! of relay2L, back contact ll of relay of ZWZ, and windingof relay ZLS, to Thecorrespondencerelay ZNCR is normally maintained energized in accordancewith the normal v position of the track switch 2 by the energiization ofa circuit closed from including front contact 12 of relay ZWP, polarcontact 13 of relay Each of the ZWP in a right hand position, backcontact M of relay 2R, and winding of relay ZNCR, to The polar neutralswitch repeater relay 2WP is energized in accordance with the normallocked position of the switch machine ZSM over control wires [5 and I6extending from the relay TWP in the control ofiice to the switch machineZSM at the track layout.

The circuit breaker C13 is energized under normal conditions, inaccordance with the normal condition of each of the polarcross-protection relays P, by the energization of a circuit closed fromincluding the upper winding of circuit breaker CB, bus wire H, anormally closed contact of the relay P for each of the switch machinesnot illustrated in detail, such contacts being connected in the circuitin series, normally closed contact [8 of the cross-protection 2P, wireI9, and lower winding of circuit breaker CB, to

A circuit is also closed but not energized under normal conditionsincluding the control wires for operation of each of the track switchesaway from its last operated position. Such closed circuit includes thewinding of the cross-protection relay P for that track switch. Thus, forexample, a circuit is closed including the reverse control wire ZRW forthe switch machine ZSM extending from the right hand terminal of thewinding of the cross-protection relay 2? including back contact 20 ofrelay 20R, magnetic blowout coil 2!,

center winding b of the overload relay 20L, con-- trol wire ZRW, reversecontact 22 of the circuit controller of switch machine ZSM, armature Aof switch machine ZSM, contact 23 of the circuit controller of switchZSM, field winding F of switch machine 28M, brakeBR of switch machineZSM, crank contact CM of switch machine ZSM, and common control wireZCW, to left hand terminal of the winding of the cross-protection relay2P.

Route estabZishment.In accordance with the principles of the routeestablishing means used in this embodiment of the invention, an operatorin setting up a route designates the entrance point thereof by thedepression of the entrance button for that point. -The entrance relayNR, associated therewith, responds, and is maintained energized as longas the route is to be maintained established. Responsive to the pickingup of a relay NR, a preselecting relay Y is picked up for each trackswitch that can be trailed in a normal position in an available routefrom the entrance point which has been designated. The selectiveenergization of the Y relays therefore, in a circuit networkconveniently called an initiating network, provides a closed circuitportion which corresponds to each available route extending from theentrance point which has been designated. Such circuit portion feedsenergy from a front contact of the entrance relay NR which is energizedto each of the exit relays m that can be included in an available routeextending from such entrance point, thus conditioning such exit relay sothat it can be energized if that point is designated by the operator asthe exit end of the route to be established. After an exit relay XR ispicked up, a stick circuit is closed for maintaining such relayenergized, dependent for deenergization upon the dropping away of theentrance relay NR for the entrance end of that route.

Responsive to the picking up of each of the exit relays XR, a normal ora reverse switch contrack switches included in the route extendingbetween the entrance and exit points which have been designated. Theposition to which each track switch that is trailed in the routeextending from the designated entrance point, is to be operated isselected by the route selecting relay Y for that track switch which isconditioned responsive to entrance designation. The position of eachtrack switch included in the route facing the designated entrance pointis selected in accordance with its required position by the cascadeenergization of the switch control relays N and R beginning with theswitch control relays provided for the track switch nearest thedesignated exit point. Such being the case, the circuits for the trackswitches facing the designated entrance point are predetermined, inaccordance with the positions that would be required if a train were topass from the designated exit point to the designated entrance point.

Responsive to the picking up of a normal or a reverse relay N or R foreach of the track switches included in the route, a circuit is closed tocause the energization of the polar neutral switch control relay WZ forthat track switch in a manner to be hereinafter considered.

trol relay N or R is picked up for each of the 7 To consider a specificexample of how a route is established responsive to entrance and exitdesignation by an operator, assume that an operator desires to set up aroute when such route is available extending from B to C. Responsive tothe depression of the button BNB for designation of the entrance pointat B, the relay BN'R is picked up by the energization of an obviouscircuit closed at contact 8 of button BNB in adepressed position. Uponthe picking up of relay BNR, a stick circuit is closed for that relayextending from including contact 8 of button BNB closed both in a normaland a depressed position, front contact 9 of relay BNR, winding of relayBNR, and front contact 24 of the track relay ZTR, to

Upon the picking up of relay BNR a circuit is closed to cause thepicking up of relay ZY (because the track switch 2 is trailed in anormal position from the entrance point at B) extending from includingfront contact 25 of relay BNR, back contact 26 of relay BXR, backcontact 21 of relay 2R, and winding of relay ZY to Upon the picking upof relay 2Y a circuit is closed extending to the winding of relay CXR tocondition that relay for energization so that, upon the depression ofbutton CXB, such relay is picked up by the energization of a circuitextending from including front contact 25 of relay BNR, back contact 26of relay BXR, back contact 21 of relay 2R, front contact 28 of relay ZY,wire 29, winding of relay CXR, back contact 30 of relay CNR, and contact3i of button CXB closed in a depressed position, to The picking up ofrelay CXR closes a stick circuit at front contact 32 to shunt contacts3!] and 3| out of the circuit just described.

Responsive to the picking up of relay CXR, a circuit is closed to causethe picking up of relay 2N (selected in accordance with the picked upposition of relay Y) extending from including front contact 33 of relayCXR, wire 34, front contact 35 of relay 2Y, upper winding of relay 2N,and back contact 36 of relay 2R, to The picking up of relay 2N causesthe positioning of the track switch 2 in a manner to be hereinafterdescribed, and after such track switch has been properly positioned, thesignal B governing entrance to the route extending from B to C iscleared.

If there were other track switches included in the route,,as isdisclosed, for example, in the 'above mentioned patent to A. Langdon,Patent No. 2,148,865, the picking up of a switch control relay such asrelay 2N would close a front contact of a circuit for the energizationof a normal or a ..ner, such mode of operation being effective until theposition of each of the track-switches included in the route beingset upis definitely selected by the energization 'of an N or R relay'for suchtrack switch.

Switch operation.After the position of a track switch is selected by thepicking up of a relay N or R for that track switch, the polar neutralrelay WZ for such track switch responds and causes the energization of anormal or reverse switch control relay CN or CR, dependent upon theposition to which the track switch is to be operated. The picking up ofa relay CN or CR closes a respective normal or reverse switch controlcircuit and appliesenergy to the switch machine for which such controlrelays are provided in a manner to cause that switch machine to beoperated to the required position, the energization of such controlcircuit being effective to act upon a winding of the overload relay, Lfor that track switch to provide overload protection.

To consider a specific example of how a switch machine SM is operated inaccordance with the picking up of an N or R relay in the selection of aroute, assume that an operator causes the establishment of ,a route inaccordance with'principles as heretofore set forth requiringthe positionof the track switch 2 to be reverse as required in seting up a routeextending from A to C. The picking up of relay 2R in the establishmentof such route causes the energization of the lower winding of relay ZWZby a circuit closed from including front contact 31 of relay 2L, frontcontact 38 of relay 2R, and lower winding of relay 2WZ, to; Theenergization of relay ZWZ in accordance with the closing, of thatcircuit causes its polar'contacts to be operated to a left hand positionand thus close a circuit for the reverse control relay CR extending fromincluding contact 39 of circuit breaker CB, contact 4B of circuitbreaker CB, front contact 4| of relay ZLS, front contact 42 of relay2TH, front contact 43 of relay 2WZ, polar contact 44 of relay 2WZ in aleft hand position, wire45, back contact 46 of overload relay 20L,winding of relay 2CR, wire 41, front contact 48 of relay 2L8,

Upon the picking up of the reverse switch control relay ZCR, a switchoperating circuit is closed for the switch machine 28M extending fromincluding contact 39 of circuit breaker CB, contact 40 of circuitbreaker CB, front contact 4| of relay 2LS, wire 54, front contact ofrelay ZCR, magnetic blowout windingZI, winding b of overload relay 20Lconnected in multiple with the thermal resistor 55, reverse control wireZRW, contact 22 of the circuitcontroller of switch machine 28M, armatureA of the motor of switch machine ZS'M, contact 23 of the circuitcontroller, of switch machine 28M, field winding F of switch machine28M, brake BR of switch machine 28M, crank circuit controller GM ofswitch machine ZSM, common control wire ZCW, wire 41, front contact 480f relay 2LS,

contact 49 of circuit breaker CBfand contact 50 7 Q of circuit breakerCB, to

When relay 2R is picked up in the establishmentof the route, thev relay2NCR is dropped away by the opening of the circuit for that relay atback contact I l, and the dropping away of that relay closes a stickcircuit for the relay 2LS to maintainsuch relay energized until theoperation of the-switch machine 28M has been completed, extending from,including front contact Id of relay 2L, back contact 5| or relay ZNCR,back contact 52 of relay ZRCR, front contact 53 of relaylLS, and windingof relay ZLS,

to l

front contact 49 of circuit breaker CB, and con- 'tact 5c of circuitbreaker CB, to

2NW, contact bar 22 of switch machine 2SM,

armature A of switch machine ZSM, contact 23, of the pole changingcircuit controller, field winding F of switch machine 2SM, brake BR ofswitch machine 23M, crank contact CM of switch machine 2SM, and commoncontrol wire ZCW to the left hand terminal of the cross protection relay2P. The polarity applied to such circuit is, of course, opposite to thepolarity required for the operation of the motor of the switch machineZSM in the same direction of rotation, so thus the energy applied to thenormal control WireZNW' during the period when the dynamic braking iseffective is of a negative polarity and therefore provides that energyflows through the winding of the cross'protectio'n relay 2P in adirection not effecting its operation. Energy flowing through thatcircuit at that time maintains the brake BR energized and thus preventsits application until the motor has practically come to a stop.

After the motor of the switch machine ZSM has come to a stop, the brakeBR is deenerg'ized and becomes effective to prevent the rotation of thearmature A until energy is again applied to a control circuit for theswitch machine 28M.

After the track switches are locked in their reverse positions, therelay ZWP is picked up with its polar contacts operated to a left handposition in accordance with the polarity selected by the point'detectorcontact mechanism in the switch machine 2SM.' The picking up of'relay2WP closes a circuit for the correspondence relay 2RCR extending fromincluding front contact l2 of relay 2WP, polar contact l3 of relay. ZWPin a left hand position, winding of relay ZRCR, and back contact 59 ofrelay 2N, to (9-) Upon the picking up of relay ZRCR, the stick circuitfor relay 2LS is opened at back contact 52 to cause such relay to dropaway;

The opening of front contacts H and 43 of relay ZLS removes energy from'the reverse control circuit for the switch machine {SM and causes thedropping away of relay 203. The reverse control circuit for the switchmachine 28M has, however, been opened prior to the dropping away ofrelay 2LS by the shifting'of contact 22 of the pole changing circuitcontroller of the switch machine ZSM.

It is provided by a stick circuit for the relay 2WZ that once theoperation of the switch machine ZSM has been initiated, an opportunityfor the switch machine to complete its operation is provided,irrespective of the restoration of the route establishing means. Thus,to consider the condition just described with reference to theestablishment of a route from A to C, a stick circuit is closed as soonas the relay ZWP is dropped away when the switch machine ZSM starts itsoperation extending from including front contact 31 of relay 2L, backcontact 60 of relay ZWP, front contact 6| of relay 2WZ, polar con tact62 of relay 2WZ in a left hand position, and lower winding of relay 2WZ,to It will be seen that restoration designation by an operator to causethe dropping away of relay 2R will not be effective to cause thedropping away of the relay 2WZ until the switch machine ZSM hascompleted its operation to its reverse position.

It is believed obvious from the detailed description with relation tothe operation of the switch machine 2SM from its normal to its reverseposition that a similar mode of operation is effective for causing theswitch machine 28M to be operated from its reverse to its normalposition as required when a route is established extending from B to Crequiring track switch 2 to be operated from a reverse to a normalposition. Under such conditions the relay 2N is picked up, and thepicking up of that relay causes the relay 2WZ to be energized by acircuit closed from ,including front contact 31 of relay 2L, frontcontact 63 of relay 2N, and upper winding of re- Upon the picking up ofrelay 2N, the relay 2RCR is dropped away by the opening of back contact59. picked up with its polar contacts operated to their right handpositions, .the relay 2CN is picked up by the energization of a circuitclosed from including contact 39 of circuit breaker CB, front contact 40of circuit breaker CB,

front contact 4! of relay 2LS, front contact 42 .of relay 2TR, frontcontact 43 of relay 2WZ,

polar contact 64 of relay 2WZ in a right hand position, wire 65, backcontact 66 of relay L. winding of relay 2CN, wire 41, front contact 48of relay 2LS, front contact, 49 of circuit breaker CB,

and contact 50 of circuit breaker CB, to

When relay 2CN is picked up, energy is applied to the motor of theswitch machine 2SM for operation to a normal position by a circuitclosed from including contact 39 of circuit breaker CB, front contact ofcircuit breaker CB, front contact 4| of relay 2L8, wire 54, frontcontact 56 of relay 2CN, magnetic blow-out winding 51, winding 0 ofrelay 20L connected in multiple with resistance 58, normal control wire2NW, contact 22 of the pole changing controller of switch machine ZSM,armature A of switch machine 2SM, contact 23 of the pole changingcontroller of switch machine ZSM, field winding F of switch machine 2SM,brake BR of switch machine 2SM, crank contactor GM of switch machine2SM, common control wire 2CW, wire 41, front contact 48 of relay ZLS,front contact 49 of circuit breaker CB, and contact of circuit breakerCB, to

After the switch machine has completed its operation to its normalposition, the pole changing circuit controller of that switch machineoperates contact 22 to a position to open the con- When relay 2WZ is itrol circuit just described, and closes a circuit for the dynamicbraking of the switch machine motor extending from the right-handterminal of the cross protection relay 2P including back contact 2B ofrelay 2CN, magnetic blowout winding 2|, winding 6 of overload relay 20Lconnected in multiple with resistor 55, reverse control wire ZRW,contact 22 of the pole changing controller of switch machine 28M,armature A of switch machine 28M, contact 23 of the pole changingcircuit controller of switch machine 28M, field winding F of switchmachine 25M, brake BR of switch machine 2SM, contact CM of switchmachine ZSM, and common wire 20W to the lefthand terminal of the crossprotection relay 2P. Such circuit remains closed but is deenergizedafter the armature A of the motor of switch machine ZSM has ceased torotate, and thus the brake BR becomes effective for holding the armatureA of the switch machine ZSM in its last operated position.

After the switch machine 23M has been operated to its normal positionand the track switch 2 has been locked, the relay 2WP is picked up withits polar contacts operated to a right-hand position, and the picking upof that relay causes the energization of relay ZNCR. When relay ZNCR ispicked up, the stick circuit for relay 2LS is opened at back contact 5|,and the dropping away of that relay causes the release of relay 2CN byopening the circuit for such relay at front contacts 4| and 48. Theopening of those contacts also of course removes energy from the normalcontrol circuit for the switch machine 2SM.

It will be noted with reference to Fig. 1A that the relays 2N and 2B canalso be energized upon the actuation of the auxiliary control lever ZSMLto respective normal and reverse position, thus providing an auxiliarycontrol for each of the track switches which is effective, irrespectiveof the establishment of routes.

Signal controls.In order to provide that a signal can be cleared for aroute only after such route is completely set up, circuit selections areprovided for the control of the signals by the correspondence relays NCRand RCR, and the lockstick relay LS for each of the track switches.Inasmuch as it has been pointed out that a relay LS is dropped awayafter its track switch has completed its operation to its requiredposition, it will be noted that the signal B, for example, is clearedonly after a route is completely set up from B to C dependent upon theenergization of relay BG by a circuit closed from including frontcontact 61 of relay CXR, wire 68, front contact 69 of relay 2TB, backcontact if! of relay 2LS, back contact H of relay 2RCR, front contact 12of relay ZNCR, back contact 13 of relay BXR, front contact 74 of relayBNR, and winding of relay BG, to The picking up of that relay causes theextinguishing of the red lamp and the illumination of the yellow lamp ofsignal B upon the shifting of contact 15 to cause such signal to displaya proceed indication.

It is believed to be obvious from the example just described how each ofthe signals can be cleared after a route which it governs has beencompletely set up, the same circuit selections provided by the contactsof the correspondence and lock-stick relays being used for theenergization of signal control relays for signals governing bothdirections of trafiic.

Restoration to n0rmaZ.The restoration of the parts of the systemassociated with the establishis designated by an operator.

' train has left the track section 2T, the restoration ment of a routeto their normal conditions can be effected either upon the manualdesignation of such restoration by an operator, or automatically uponthe passage of a train through the route established. V

Asa typical example of "how manual restoration is effective, assume thata route has been setup as has been described extending from B to C, andthe signal B governing entrance to that route has been cleared. Therestoration to normal of the parts of the system associated with theroute set up can be initiated by the pulling out of the entrancebuttonBNB forthe entrance end of such route. The pulling out of that buttoncauses the dropping away of the relay BNR by opening the stick circuitfor that relay at contact 8, and the dropping away of relay BNR causesthe dropping away of relay BG by opening the circuit for that relay atfront contact "it. The dropping away of that relay of course opens frontcontact E5 to cause the restoration to stop of the signal B.

The dropping away of relay BNR also causes the dropping away of relaysZY and CXR by opening the circuits for such relays at front contact 25,and the dropping away of relay CXR, opens the pick-up circuit which'hasbeen described for the switch position selecting relay 2N. Upon therestoration of the signal B to stop, the lock relay 2L can be energizedbecause of the restoration of the route locking, approach or timelocking provided,

and the picking up of that relay opens a stick circuit which is closedas long as the electric looking is effective for relayEN extending fromincluding front contact 16 of relay 2N, back contact ll of relay 2L,center winding of relayZN, and back contact 56 of relay 2R, to Thedropping away of relay 2N completes the restoration to normal of theparts of the system associated with the establishment of the route fromB to C, the relay 2W Z having been dropped away as soon as the lockrelay 2L was deenergized upon the clearing ofthe signal B governingentrance to the route. at that time would of course cause therestoration of the switch control relay ZCN by opening the circuit forthat relay at front contact 43.

If restoration is to be automatic, dependent upon passage of a train, avery similar mode of operation is eifective, the entrance of the traininto the route extending from B to C being effective to cause thedropping away of relay BNR. by opening the stick circuit for that relayat front contact 28. The dropping away of relay BNR causes therestoration to stop of the signal B and the restoration of the otherrelays as described except that the relay 2L remains dropped awaybecause of the presence of the train in the route.

Such relay when dropped away maintains the stick circuit described forrelay 2N energized in order that the contacts 18 and'lil willbemaintained open toprevent the so-called preconditioning of a conflictingroute such as the route extending from A to C. The opening of thosecontacts prevents the energization of either relay CXR or relay AXRresponsive to entrance and exit designation, thus providing thatentrance and exit designation for the establishment of a route can beeffective only when such route is available for use at the time the exitend thereof As soon as the of the route locking allows the energizationof the relay 2L, and the picking upJof that relay allows the droppingaway of the relay 2N by opening the stick circuit for that relay at backcontact 11.

Overload protection-4f an overload occurs in the switch control circuitduring the operation of a switch machine other than just a momentaryoverload, the energization of a b orcwinding of the overload relay 0L(dependent upon the position to which the switch machine is beingoperated) causes the picking up of that overload relay,

andsuch relay in picking up closes a stick circuit for maintaining itenergized until restoration is effected by an operator. Upon the pickingup of the overload relay under such conditions, the circuit for the ONor CR relay energized at that time is opened, and the dropping away ofthat relay breaks the control circuit for its switch machine SM, suchcircuit being opened by heavy duty magnetic blowout contacts that areconstructed to most effectively open the circuit carrying an abnormallyhigh amount of current.

As an example of such mode of operation,if the track switch is beingoperated from its normal to its reverse position as described when anoverload occurs, the picking up of relay L due to an abnormal amount ofcurrent flowing inthe switch control circuit closes a stick circuit forthe upper The dropping away of the relay ZWZ Y 2W2 in a left handposition, front contact 48 of .relay ELS, frontcontact Q9 of circuitbreaker CB,

and contact 59 of circuit breaker CB, to

The picking up of the overload relay ZOLopenS the circuit for thereverse control relay 'ZCR at back contact 46, and the dropping away ofthat relay opens the reverse control circuit for the motor of the switchmachine ZSM at front contact 20.

An operator is aware of an overload condition in the operation of thetrack switch by the usual out-of-correspondence indication displayed byan indicator lamp (not shown) on the control panel of the controlmachine and in View of such condition he will cause the restoration tonormal of the parts of the system conditioned for the route requiringthe operation of the switch machine 23M to its reverse position. Inrestoring those relays to normal, the relay ZWZ is maintained energizedby a stick circuit after such restoration because of the deenergizedcondition of relay 2WP. To cause the operation of the switch machine 2SMback to its normal locked position, the operator causes the energizationof the switch position selecting relay 2N which in picking up energizesthe upper winding of relay ZWZ with a polarity to oppose the flux set upin that relay by the energization of the lower winding, and thus causesuch relay to be dropped away and to operate its polar 7 circuit. Withrelay 20L in a dropped away posiof the switch machine 2SM is effectedbecause of the energization of the winding NP of such pole changer. Theenergization of winding NP is effected because contact 82 of the circuitcontroller is in its dotted position at that time.

It is believed to be readily apparent to those familiar with the artthat the operator can cause the switch machine to be operated back andforth as required to free the track switch of obstructions or toovercome other difiiculties which could have been the cause of theoverload originally encountered in the operation of the switch machinefrom its'normal to its reverse position.

It will be noted that the breaking of the switch machine controlcircuits under conditions where an overload occurs, or where reversal inmidstroke is effected without such overload, opens the control circuitby heavy duty contacts provided with magnetic blowout means forextinguishing the arc.

Cross protection-The use of a cross protection relay P in the controloffice for each of the track switches provides that a cross between thecontrol wires of any two track switches in the field that could cause anunauthorized operation of one of such track switches will be immediatelydetected as soon as energy is applied for the operation of either of thetrack switches involved, and the response of the cross protection relayP under such conditions causes the immediate opening of the circuitbreaker CB to deenergize the switch machine control circuits.

As an example of how such cross protection is provided, assume thatenergy is applied to the reverse control wire 3RW for the switch machine3SM in a manner comparable to that which has been described for theenergization of the reverse control wire ZRW of the switch machine 25M,and assume at that time that a cross exists in the line wires asindicated by the dotted line 8|. The positive energization of thecontrol wire ZRW due to such cross at a time when the switch machine ZSMis in its normal position causes energy to flow from the cross includingcontrol wire ZRW, winding b of overload relay 20L connected in multiplewith resistor 55, magnetic blowout winding 2!, backcontact 20 of relayZCR, winding of cross protection relay 2P, wire 41, front contact 48 ofrelay ZLS, front contact 49 of circuit breaker CB, and contact 50 ofcircuit breaker CB, to Thus, a circuit is completed for the energizationof the cross protection relay 2P energized with a polarity that willcause its operation to open the circuit for the circuit breaker CB atcontact [8, and 'thus cause the deenergization of the switch controlcircuits by the opening of the circuit breaker contacts. The opening ofthe circuit breaker will of course provide an indication for theoperator to call his attention to the condition, and upon examining thepolar relays the operator can determine which of the switch machines isinvolved in the cross occurring betweenthe switch machine controlcircuits. After the defective condition has been remedied, the operatorcan restore the cross protection relay 2P by the actuation of therestoration button on such relay, and the restoration of that relay willallow the restoration of the circuit breaker CB, such circuit breakerbeing of the type that can be restored only when its windings can beenergized at a time when manual restoration by an operator is effected.

In a similar manner, if positive energy from another switch circuit wereapplied by a cross to the normal control wire 2NW with the track switch2 in its normal position, the cross protection relay 2P would also betripped because of the flow of energy from including wire ZNW at thepoint where the cross occurs, resistance 58 connected in multiple withthe winding 0 of the overload relay 20L, magnetic blowout winding 57 ofrelay ZCN, back contact 56 of relay ZCN, winding of the cross protectionrelay 2P, wire 41, front contact 48 of relay ZLS, front contact 59 ofcircuit breaker CB, and back contact 50 of circuit breaker CB, to It isbelieved from the typical examples described when the track switch 2 isassumed to be in its normal position, it will be readily apparent thatsuch circuits are also effective for cross protection when the trackswitch 2 is in its reverse position to prevent its unauthorizedoperation.

Having thus described in detail as a specific embodiment the control forthe track switches of a simple track layout, it is desired to beunderstood that this form is selected to facilitate in the disclosure ofthe present invention rather than to limit the forms that the presentinvention may assume, and it is to be further understood that variousadaptations, alterations and modifications may be applied to thespecific form shown without in any manner departing from the spirit orscope of the present invention except as limited by the appended claims.

What I claim is:

1. In a switch and signal control system of the character described forthe power operation of each track switch of a track layout upon themanual designation at a control office of the entrance and exit ends ofeach route extending over such track switch; route establishing means atthe control office including normal and reverse switch positionselecting relays for each of the track switches responsive to thedesignation of the respective entrance and exit ends of each of theroutes for selecting the position of each of the track switches requiredto set up such route; a polar cross protection relay at the controloffice for each of the track switches; a circuit breaker at the controloffice; a power switch machine for each of the track switches; normaland reverse control wires for each of said power switch machinesextending from the control office; circuit means dependent upon saidcircuit breaker including said control wires for causing the poweroperation of each of said switch machines in accordance with theposition selected by said route establishing means, such circuit meansbeing energized at the control office only when that track switch is outof correspondence with the position selected by said switch positionselecting relays, and such circuit means when inactive for controlpurposes being closed but deenergized including said cross protectionrelay and one of said normal or reverse control wires for thattrackswitch; and circuit means for energizing said circuit breaker onlywhen each of said cross protection relays has been unaffected byenergization of a particular polarity applied under abnormal conditionsto'such switch control wire.

2. In a switch and signal control system of the character described fora track layout having a plurality of conflicting routes provided by atrack switch extending between entrance and exit points; a'power drivenswitch machine for said track switch; a miniature track diagram of thetrack layout at a control ofiice having disposed thereon manuallyoperable control buttons for designation of the respective entrance andexit points route establishing means at the control ofii'ce includingnormal and reverse switch position selecting relays for said trackswitch responsive to the actuation of said contact means for therespective entrance and exit ends of each available route for selectingthe position of said track switch required for suchroute, irrespectiveof the position suchtrack has last assumed; a

.normal and a reverse switch control relay for the track switch; circuitmeans responsive to said route establishing means for energizingsaidnormal or said reverse switch control relay in accordance with thenormal or, reverse position of said track switch selected by said routeestablishing means, only if said track switch is out of correspondencewith the position selected by said route establishing means; a crossprotection relay at the control oifice; a circuit breaker at the controlofiice; normal and reverse control wires extending from the controloffice to said switch machine; switch operating circuit means responsiveto the energization of saidnormal or said reverse switch control relayincluding one or the other of said control wires for operating saidswitch machine to a position corresponding to said normal or reverseswitch .control relay energized, such circuit means when inactive forcontrol purposes being closed but deenergized including said crossprotection relay and one of said normal and reverse control wires forthat track switch; and circuit means for energizing said circuit breakerexcept when said closed circuit means including said cross protectionrelay is abnormally energized with a particular polarity. i

3. In a switch and signal control system of the entrance-exit type forthe power operation of a track switch uponthe manual designation at acontrol office of the entrance and exit ends of each route desired to beestablished extending over such track switch, routev establishing meansat the control ofiice including normal and reverse switch positionselecting relays for said track switch effective upon the designation offrom the control ofiice'to the switch machine,

switch operating circuit means responsive to the selection of a normalor a reverse position for the track switch by said route establishingmeans including said normal or said reverse control wire for operatingsaid switch machine to a corresponding position, and circuit meansrendered effective when said track switch has been properly positionedin accordance with theposition selected by said route establishing meansto deenergize one of said control wires at the control oflice and toclose a circuit including the other of said control wires to shunt themotor of said switchmachine.

4. In a switch and signal control system of the entrance-exit type for atrack layout, providing by a track switch governed from a control officea plurality of conflicting routes extending between entrance and exitpoints; manually operable contact means at the control ofcharacterdescribed for a track layout providing,

exit points designated by the actuation of said contact means; a normaland a reverse switch control relay at the control office for said trackswitch; circuit means eifective in response to the selection of a normalor a reverse position for said track switch by said route establishingmeans for energizing the corresponding normal or reverse switch controlrelay, only if said track switch is out of correspondence withthe'position selected by said route establishing means; an electricmotor driven 'switoh machine for saidtrack switch; a normal and areverse control wire extending from thecontrol office to said switchmachine; switch operating circuit means including said normal andreverse control wires effective to operate said switch machine to aposition corresponding with the normal or reverse switch control relayenergized; and circuit means rendered effective when said track switchis in correspondence with the position selected by said routeestablishing means'to deenergize one of said control wires at thecontrol oflice and to close a shunt circuit for the motor of said switchmachine including the of said control wires.

, 5, In a switch and signal control system of the character describedfor a track layout providing by a track switch a plurality ofconilicting routes extending between entrance and exit points, manuallyoperable contact means at a control oflice for designation of therespective entrance and exit points, route establishing means at thecontrol ofiice including normal and reverse switch position selectingrelays for said track switch effective in response to the designa-e tionof therespective entrance and exit points of each of the routes toselect the position of said track switch required for such route, anormal and a reverse switch control relay at the control office for saidtrack switch, circuit means responsive to the selectionof a position forsaid track switch by said route establishing means for energizing saidnormal or said reverse switch control relay in accordance with thenormal or the reverse position of said track switch selected 1 bysaidroute establishing means, only if such track switch is out ofcorrespondence with the position selected by said route establishingmeans, an electric motor driven switch machine for said track switch, anormal and a reverse control wire extending from the control office tosaidswitch machine, a polar cross protection relay at the control ofiicefor said track switch,

switch operating circuit means including said normal and reverse controlwires responsive to" the energization of said normal or said reverse,switch control relays for operating said'switch machine to acorresponding position, and circuit means rendered efiective whensaid'track switch has been properly positioned in accordance with theposition selected by said route establishing means to deenergize one ofsaid control wires at the control office and to close a circuitincluding the other of said control wires and said cross protectionrelay to shunt the motor of said switch machine.

6. In a switch and signal control system of the by a track switch aplurality of conflicting routes extending between entrance and exitpoints; an

electric motor driven switch machine for said .5

track switch; a miniature track diagram of the track layout at a controloffice having disposed thereon manually operable contact means fordesignation of the respective entrance and exit other such route; anormal and a reverse switch control relay at the control ofiice for saidtrack switch; circuit means responsive to said route establishing meansfor energizing said normal or said reverse switch control relay inaccordance with the respective normal or reverse position for said trackswitch selected by said route establishing means, such energizationbeing effective only when said track switch is out of correspondencewith the position selected by said route establishing means; a polarcross protection relay at the control office for said track switch; acircuit breaker at the control ofiice; a normal and a reverse controlwire extending from the control oifice to said switch machine; switchoperating circuit means including said normal and reverse control wireseffective to operate said switch machine to a normal or a reverseposition in accordance with the energization of a respective normal orreverse switch control relay; circuit meansrendered efiective when saidtrack switch is in correspondence with the position selected by saidroute establishing means to de-energize one of said control wires at thecontrol ofiice and to close a shunt circuit for the motor of said switchmachine including the other of said control wires and said crossprotection relay; and circuit means for energizing said circuit breakerexcept when said shunt circuit including said cross protection relay isenergized with a polarity opposite to that generated by the free run ofsaid'motor after driving energy has been removed. 7

'7. In a switch and signal control system of the character described forthe establishment of each route extending through a track layout whichprovides by at least one power switch a plurality of conflicting routesextending between entrance and. exit points; manually operable contactmeans for designation of each of the entrance and exit points; normaland reverse switch position selecting relays for each of the trackswitches; a polar neutral switch control relay for each of the trackswitches; a normal and a reverse switch control relay for each of thetrack switches, each of such switch control relays having contacts ofrelatively high current carrying capacity; an electrically operatedswitch machine for each of the track switches; route establishing meansresponsive to the designation of each of the exit points, subsequent tothe designation of the entrance end of an available route extending tosuch point, for selectively energizing one of said switch positionselecting relays, the relay selected being dependent upon the positionof the track switch required, for each track switch included in theroute extending between such designated entrance and exit points;circuit means responsive to the energization of a switch positionselecting relay for each of the track switches for distinctivelyenergizing said polar neutral relay in accordance with the positionselected by said route establishing means for that track switch; circuitmeans dependent upon the energized condition of said polar neutral relayfor each of the track switches for energizing said normal or reverseswitch control relay for that track switch, the

- relay selected being dependent upon the polarity by which such polarneutral relay is energized; circuit means responsive to the energizationof said normal or said reverse switch control relay for each of thetrack switches for operating said electric switch machine for that trackswitch to a corresponding position, such circuit means including acontactor in the switch machine effective to break the operating circuitof such switch machine when it has completed its operation; and overloadswitch control means for each of the track switches effective to causethe release of said normal or said reverse switch control relay for thattrack switch when said switch machine for that track switch draws anabnormal amount of current in operation, whereby said contactor at eachof said switch machines breaks the switch control circuit each time theswitch machine has completed its operation, and said normal or reverseswitch control relay breaks the circuit for said switch machine whenthere is an overload.

8. In a switch and signal control system for railroads; a track layouthaving a track switch governed from a control office; manually operableswitch control means at the control olfice having operating positionsfor designation of the respective normal and reverse positions of saidtrack switch; normal and reverse switch control relays at the controlofiice for said track; circuit means for energizing said normal or saidreverse switch control relay when said manually operable switch controlmeans is actuated to a respective normal or reverse operating position,only if that track switch is out of correspondence with the positionthus designated; a polar cross protection relay at the control ofilce; acircuit breaker at the control oilice; a power switch machine for saidtrack switch; normal and reverse switch control wires extending from thecontrol office to the track switch; switch control circuit meansresponsive to the energization of said normal or said reverse switchcontrol relay including one or the other of said control wires foroperating said switch machine to a corresponding position, such circuitmeans when inactive providing a closed circuit including one of saidline wires and said cross protection relay; and circuit means forenergizing said circuit breaker, only when said cross protection relayis unaffected by the energization of said switch control circuit meanswhen such means is inactive for the designated power operation of saidtrack switch..

9. In a switch and signal control system for railroads, a track layouthaving a track switch governed from a control oflice, a manuallyoperable switch control lever at the control ofiice having operatingpositions for designation of the respective normal and reverse positionsof said track switch, a polar cross protection relay at the controloflice, a circuit breaker at the control ofilce, a power switch machinefor said track switch, normal and reverse switch control wires extendingfrom the control ofilce to the switch machine, switch control circuitmeans responsive to the actuation of said switch control lever to anormal or a reverse operating position including one or the other ofsaid control Wires for operating said switch machine to a correspondingposition, such circuit means providing when inactive for the operationof the switch machine, a closed circuit including one of said line wiresand said cross protection relay and providing for the deenergization ofthe other control wire at the control oflice, and circuit means forenergizing said. circuit breaker only when said cross proteotion relayis unaffected by the energization of said switch control circuit .meanswhen such means is inactive for the power operation of said trackswitch.

10. In a switch and signal control system of V extending from thecontrol onice to the switch machine, switch operating circuit meansincluding said control wires effective to cause the power operation ofsaid track switch in accordance with the position selected for suchtrack switch by said route establishing means, a cross protection relayat the control oflice for said track switch, and circuit means effectivewhen said switch operating means is inactive to cause the poweroperation of said track switch for connecting said normal and saidreverse control wires contemporaneously to said common control wirethrough the winding of said cross protection relay.

11. In a switch and signal control system of the character described forgoverning from a control office the establishment of each route ex-vtending through a track layout providing by a power switch a pluralityof conflicting routes extending between entrance and exit points;manually operable contact means for designation of the respectiveentrance and exit points; route establishing means responsive to theactuation of said contact means for designation of the respectiveentrance and exit points of each of the" routes for selecting theposition required for said power switch in such route; normal andreverse switchcontrol relays for said power switch; circuit meansforselectively energizing said normal and reverse switch control relays inaccordance with the position selected by said route establishing means,such circuit means being effective only if said track switch is out ofcorrespondence with its selected position; normal and reverse and commonswitch control Wires extending from the control office to the powerswitch; a cross protection relay at the control office for said powerswitch; and switch operating circuit means including said control wireseffective, in response to the energization of one of said switch controlrelays for causing the operation of said power switch to a correspondingposition, such switch operating circuit means being effective at thecontrol office when said normal and reverse switch control relays areboth deenergized to connect said normal and said reverse control wirescontemporaneously to said common control wire through the Winding ofsaid cross protection relay.

CHARLES L. SWANTON.

